Direct Method of Preparation of Dodecanesulfonamide Derivatives and Some Surface Properties

Alkanesulfonamide compounds are known as surfactants because of the presence of –SO₂NH– function in their molecule. Thus, they are used in many formulations in the chemical and textile industries and also as inhibitors of corrosion. Generally, sulfonamide derivatives are prepared using sulfonyl chlorides as the raw material. The methods often described in the literature involve the use of ammonia gas and pressure. A simple and direct method to prepare pure alkanesulfonamide derivatives possessing good surface properties is presented in this work. Thus, n-dodecanesulfonyl chlorides obtained by photochemical sulfochlorination of n-dodecane under visible light using sulfuryl chloride were separated from the reaction mixture. These sulfonyl chlorides, a mixture of primary and secondary isomers, were transformed in one step into N-ethyldodecanesulfonamides, N-ethanoldodecanesulfonamides and the salts of dodecanesulfonamidoacetic acid. After purification on chromatographic column, the six position isomers of these sulphonamide derivatives were analysed and well separated by gas phase chromatography using a nonpolar column. Then, gas phase chromatography analysis coupled to mass spectrometry using electronic impact (GC/MS/IE) was performed to identify the different position isomers. The primary isomers of sulphonamide derivatives were identified by crossed injection of the compounds obtained by synthesis from the 1-chlorododecane using the Grignard reagent, and identified by IR, ¹H- and ¹³C-RMN, elementary analysis and GC/MS/IE. Some physico-chemical properties of these sulphonamide derivatives were examined. The variation of surface tension versus the concentration of both primary and secondary sulphonamide derivatives were studied, and the critical micellar concentration was determined for the compounds showing surface activity. The foaming power was also determined by the Bartsch method, and the results obtained were compared to those of a commercial surfactant, the linear alkylbenzenesulfonate. The stability of the foam formed was also evaluated.

Amel TazeroutiEmail: